The invention relates to a method and a device for determining plasma characteristics, the method comprising the steps of: - arranging a measurement probe (2) having a self-inductance in proximity to a plasma (3) to establish inductive coupling between the plasma (3) and the measurement probe (2); - determining a mutual inductance (Mprobe/plasma) between the measurement probe (2) and the plasma (3); - depending on the mutual inductance (Mprobe/plasma), estimating a quantity representing the plasma complex conductivity (σ); and - deriving at least one plasma parameter from the plasma complex conductivity (σ).